from sys import argv

try:
    script, f = argv
    f = int(f)
except ValueError:
    f = 5

def fib(N:int):
    """ Функция считает
        N-е число Фибоначчи

    """

    fibList = [0, 1] + [0] * N

    for i in range(2, N+1):
        fibList[i] = fibList[i-1] + fibList[i-2]

    return fibList[N]

print(fib(f))
